The present invention relates to an air humidifier for moisturizing the air in a dry treatment device for photographic material, such as X-ray film cassette loading and unloading devices or image screen receiving devices for automatic film supply in a film platform.
Air humidifiers of the above mentioned general type include a housing with at least one air aspirating opening and at least one air discharge opening, a moisturizable foam material plate, and a ventilator which blows air through the foam material plate and then through the air discharge opening to a space to be moisturized.
The known air humidifiers of the above mentioned general type operate in accordance with a "evaporation principle". An axial fan produces an air stream which passes through a moisturized foam material plate arranged perpendicularly to the stream. The air which is blown through the foam material plate takes water from it because of the diffusion gradient, so that the moisture is blown into the space to be moisturized. In this operation a drop formation or the formation of condensation water is precluded.
This moisturizing principle is suitable for the inner moisturizing of devices for dry treatment of photographic materials. In these devices, such as for example X-ray film cassette loading and unloading devices, air to be dried leads to electrostatic charging of the photographic material which during the discharge leads to so-called accidental exposure of the film. This electrostatic charging can be avoided only by an air humidifier. The above described known device has the disadvantage that the fixedly arranged foam material plate has dimensions of approximately 15 cm.times.35-40 cm.times.1 cm for producing the above described action. Thereby the dimensions of the known air humidifiers are high, so that its mounting in or arrangement on the X-ray cassette loading and unloading devices or image screen receiving devices with an automatic loading and unloading of the film platform with a sheet film of required formats, encounters considerable difficulties. In addition, an absolute light-tight connection of the big humidifier with the inner space of the dry treatment device is required.